Unit base construction



' June 23, 1931.

A. .P. BALL UNIT BASE CONSTRUCTION Original Fiied July 19, 1920 4 Sheets-Sheet 1 June 23, 1931. A. P. BALL 1,811,252

UNIT BASE CONSTRUCTION Original FilgdJuly 19. 1920 4 Sheets-Sheet 2 June 23, 1931.

UNIi BASE CONSTRUCTION Original Filed July 19; 1920 4 Sheets-Sheet 3 A. P. BALL 1,811,252

June 23, 1931. T 'A P BA| 1 1,811,252

UNIT BASE CONSTRUCTION original Filed July '19, 1920 4 Sheets-Sheet 4 Patented June 23, 1931 UNITED STATES PATE I OFF-ICE.

ALBERT P. OI DETROIT, HIGBIGAN, ASSIGNOR TO SQUARE D COMPANY, O]?

\ DETROIT, MICHIGAN, A. CORPORATION OF MICHIGAN UNIT BASE CONSTRUCTION original application filed July 19, 1920, Serial 1T0. 897,261. Divided and this application filed Mal-e11 7,

Y My invention relates to electrical appara-' tus such as switches and other devices of analogous character in WhlCh conductmg members ,or' current-carrying parts are mounted upon insulating bases or blocks.

My invention relates more particularly to the construction of these insulating bases or blocks, and the manner in which the conductor members are carried thereon.

It will be apparent, as the description proceeds that my invention is not to be limited to any particular type of electrical apparatus, as it may be used to advantage in other structures wherein insulatingbases 15 are essential, or in non-analogous devices wherein insulating bases are not required, but where the method, disclosed herein, of mounting members upon individual units, and of arranging and holding these units in position upon a supporting wall may be upon insulating mountin used with equal advantage.

Briefly, the invention in its simplest form comprises a novel method of supporting conductor members or current-carrying parts ,so that when it is desired to remove certain of the conductor members for replacement, it is not necessary to disturb the remaining conductor members; or the electrical connections thereof.

jaws, switch jaws, grounded neutral set-ups, etc., are insulated by a base of insulating material, such as porcelain, slate and the like. Heretofore in the art great difliculty has been experienced in the manufacture of these bases, particularly when the materials above mentioned are used. It is not necessary to take into consideration the dielectric strength of porcelain and slate, as it is extremel high. However, consideration of.

In the construction of switches, the hinge late is obj ectionable 1923. Serial No, 623,356.

These difiiculties have rendered it difiicult in many instances to produce insulation bases ofthe desired type and size, especially in larger capacity switches where slate is preferable.

It is common, at the present time, to attach the conducting members to the insulation base by means of bolts passing from the back side of the base into the conducting members, the heads of these bolts being sealed over to insulate the same from the back wall of the enclosure. Burning of the terminals and conducting members are common occurrences. When'it is necessary to replace these terminals or conductin members, a difiicult task is encountered, as it requires first disconnecting the circuit wires, then removing the screws holding the insulation base in order to free the same fromthe box and obtain access to the back side thereof, and finally, breaking away the sealing compound coverin the heads of the bolts which connect t e current-carrying members to the base in order that the particular member may be removed. It is by means of this intricate procedure that the part burned was heretofore replaced. The difficulties encountered are obvious.

My invention involves a departure from the principles involved in the prior art method and eventuates marked advantages, resulting in a saving of material as well as facilitating the removal of conducting members when replacement thereof is necessary. Aside from these features, the invention greatly reduces the cost of manufacture in many respects. It is obvious that where service requirements, as numerous as they are, require different sizes and types of bases for practically every size or kind of apparatus employed, a large stock of raw mate-v rial is necessary, if not a large stock of finished material as well. For each size of switch or different apparatus, finished bases in stock are necessary, which requires manufacturers to burden themselves with added overhead in the form of additional stock, the majority of which is really unnecessary and accumulates either through a desire to reduce production cost to a vminimum 'or through what may be termed a necessity, namely, of furnishing any type of mounting on short notice, such as in cases of emergency.

Primarily, the object of my invention is to obviate the-above disadvantages and includes the provision of an improved method of and means for, positioning the conducting members or current-carrying parts upon individual insulating mountings, and for maintaining the latter properly positioned upon-the back wall of a switch enclosure, or other form of supporting means. A further object is to provide a novel individual mounting for each conducting member in the form of a base unit capable of individually mounting upon said back wall; as well as a novel method of assembling these currentcarrying parts and insulating bases so that they may be individually secured to, and detached from, the front of the switch without dismantling the switch.

Another object is the provision of a novel, simple and improved means for securing the base units inplace in a variety of patterns in order to obtain various types of switches, although one form only of base unit may be used. However, my invention also provides for forming these base units in a variety of shapes and designs in order to increase the flexibility of this adaptation and permit unlimited use of them in this and similar constructions. In some switches, I contemplate embodying the aforesaid base unit securing means in the form of an apertured grid which lies over and down uponeach base unit in a gripping contact, while in other switches, lateral flanges are contemplated, which flanges will receive the bolts for attaching the contacts to the back wall of the enclosure. In each instance, substantially the same advantages accrue.

A further object of my invention is to provide a simple and improved means-for securing the conducting members or currentcarrying parts to these base units, so that the replacement of a conducting member will require a minimum amount of time and labor. This is one of the important features of my invention, as it eliminates what was heretofore required, viz., dismantling the switch base in order to obtain access to the back side for breaking away a compound covering the head of thebolt securing the particular part to be replaced.

The following advantages are the result of my invention: I

((1) Ability to replace a conductor memr or terminal without dismantling the entire switch or other apparatus embodying my invention;

(6) Reducing the replacement cost when any part breaks, in that a saving of labor and material is affected;

(0) Universal adaptation of the base units, as their individual character permits them to provide a wide variety of designs in base construction;

- (d) Simplicity of construction, due to the simple design of each base unit;

(6) Economy in manufacture, as the base units are relatively small and easily made; and i Lighter and less cumbersome con struction. I

I believe that I am the first to provide interchangeable base units moulded of insulating material and held in position either by a grid. or by attaching them directly to the supporting wall, and shall therefore claim the same broadly.

In order to apprise those skilled in the art how to construct and practice my invention, I shall now describe various embodiments thereof in connection with the accompanying drawings which illustrate the interchangeability of the base units and the possibility of obtaining a variety of terminal base constructions.

In the drawings:

Figure 1 is a perspective view of a switch box, the cover being removed and the walls partially broken away to disclose in detail my base construction;

Figs. 2, 3 and 4 are perspective views of the backs of switch boxes having mounted thereupon various types of unit-base securing grids;

Fig. 5 is a perspective view of a grid slipped over and engaging the shoulder of several base units;

Figs. 6, 7 and 8 are perspective views of various types of unit-base contact-supporting blocks;

Fig. 9 is an elevational sectional view of a current-carrying assembly mounted on one of my novel base unit insulating blocks:

Fig. 10 is a perspective view of an enclosure illustratin the manner of attaching the base units directly to the back wall thereof;

Fig. 11 is a similar view of the base unit employed;

Fig. 12 is a perspective view of a different form of base unit attached directly to the back wall of the enclosure; and

Fig. 13 is a similar view of this form of base unit.

In the above mentioned drawings and in the hereinafter description of my invention I have shown, and will describe, only so much of the switch mechanism per se as is necessary for an understanding of the structure wherein base units embodying my invention are utilized. It is to be understood, of course, that a supporting surface and a base unit contact block with associated current-carrying. parts, said block being secured to said surface either directly or by a grid member fitting over said block, constitute a complete operative embodiment of my inventiona I have found my invention most applicable to thejerection of base,; units for supporting switch contacts, but it may, of course, be a plicable to-many other uses and it is, there ore, proper only to indicate the character of the mechanism which is suported on the base units. As a matter. of

act, a description of the manner in which my improved base structure is embodied in a complete switch is contained in my .copending application, '.Serial No. 397,261, filed July 19,,1920, and assigned to the SquareD Company. This present ap lication is'a devision of said ap lication, rial No. 397,261 and therefore, a 1 that is shown therein with respect to a complete switching apparatus, is to be considered as a disclosure v terminal blocks 14. These in this presentapplication.

Referring now to Fig. 1', I have shown, for purposes of illustration only, my unit base structure as positioned in a switch box- 10. This box comprisesside and end walls 11 and 12, respectively, and a back or bottom 13.

In making u my unit base switches, I utilize a plurality of base unit contact or individual mounting blocks are positioned in the switch box and are heldtherein either by a gridwhich fits down'over the blocks and bears against the flanges or shoulders 16 to effect the desired securing of the blocks to the box. I find that this method of securing the blocks may, under some-circumstances, be preferable to another method which I hereinafter describe. more in detail; that is, one in which screws are passed directl through the flanges and into the back 0 the box. In either case the heretofore, mentioned advantages of the individual base unit terminal blocks are realized.

The blocks .14 are of insulatin vmaterial and I find itadvantageous in eit er of the above cases to provide them with a metallic threaded insert 18, which is set into asa or front of the blocks. j Reference'ma be had to Fig. 9 for a clearer showing '0 the manner in which these threadedinserts'are' utilized to-so secure the current-carrying parts to the front of the block that certain of the advantages, heretofore, enumerated, are realized.

both of the latter bein is novel, an

I tive structure.

The current-carrying parts mounted on the block shown in this figure comprise a switch contact 19 and wire connector 19a; mounted on a, flat piece 191) by means 0 bolts and nuts 19c and 19d, 19c and 19/, respectively. The fiatv piece 19b -issecured to the front of the block by a screw 20 which passes therethrough and into the threaded insert 18 from the front.

These parts maybe assembled either by first mounting the members. 19 and 1901 on the flat piece 19b by means of the bolts and nuts as shown, and thereafter securing the current-carrying assembly to the front; of the insulating block 14 by the screw, 20; I

or the flat piece 19?) maybe secured to the front .of the block 14 by the screw 20, the .1 bolts 19a and 19a being first secured to tho fiat piece l9b by small portions of solder its 199 and 197% respectively, u g the fla piece withits attached screws to the block 14, and thereafter placing the parts 19 and 1901 down over the projecting shanks of the screwsand tightening the nuts19d and 19 By utilizing the method just described of mounting and assembling the current-car rying parts upon the insulating base unit 14, marked advantages result because one is then enabled to secure the current-carrying parts to, and detach them from, the

front of the block, and consequently the front of the switch, individuall out dismantling the entire mec anism. I

I believe that this method of mounting current-,carr ing parts on insulating bases since it eventuates certain advanta es I hereinafter claim the said method broad y, it being noted that said currentcarryin parts are separately mounted on the individual bases of insulating material so that any one of said arts can be quickly removed without inter ering with, or dis- -mantling, the other operating portions of the switch whereby rapid, easy, and in expensive part renewal is assured.

In Fig. 1, I have shown a very simple form of switch mechanism. mounted onv these base units. Y As shown, movable blades 21 are adapted to b ridge the contacts mounted on the blocks, ghese blades bein connected by a cross-hea 22- While, as

have pointed out, this showing of'the switch mechanism is conventional because it forms no part of my invention, itwill nevertheless-be observed, thatI have shown a mechaand withi nism which comprises a, completely opera- I Referrin now to Fig. 2, I have illustrated a base member or grid 23 which is different- 1y perforated from the grid 15 in that there are six rectangular openings, instead o four, which are arranged in tandem relation of two rows of three openings each. As illustrated, this particular type of grid may be utilized with the base units 14 to build up a switch structure wherein fuses (not shown) may be utilized. Of course, the base unit apertures may vary in size as may also the base units. This, however, is a matter of desirability, and is in no wise a departure from the spirit of the base unit construction. As a matter of fact, I have shown base units associated with the grid 23 which are constructed in accordance with the disclosure of Fig. 8. These base units are substantially'the same as those of Fig. 6, but

the tops thereof are difl'erently shaped to accommodate the contacts or terminals mounted thereupon.

In Fig. 3, I have shown another type 0f perforated rid, it being noted that here the middle per orations are at right angles to the others. As shown, this base is .partic-' ularly adaptable for the reception of switch mechanism of the double throw type.

In Fig. 4, I have illustrated still another base structure in which base units, such as 14, may be utilized. Here, however, two of .the base units are arranged in a laterally extending direction across the middle of the base and a switch mechanism of a particular character is mounted thereupon. 'I

illustrate this last grid and the method of utilizing it with two laterally extending contact blocks in pairs to emphasize to what extent my invention is flexible to take care of practically any desired type of base construction. In this disclosure, one side of the switch isshown so that it will be apparent how. this particular arrangement of base units is useful in assembling the terminals of a switch. Base units 14:" constitute the .mountings which carry the terminal clips of a cartridge fuse 30. The central base unit 14, being at right angles to the outer base unit 14, electrically connects with the other central base unit 14", by a conducting strap 31 secured to conductor bars 32 by screws 33. Each base unit is provided with a bar 32 which fastens thereto by screws 20 threading into inserts 18, as described in connection with Fig. 1. wire connections 34 to each base unit. The switch terminal clips 35 are carried on base units 14 in a similar manner, the inner base units being arranged transversely to the outer ones, in this particular instance, for

the purpose of receiving conducting strap 31. The above description is given to illustrate the utility of the base units in carrying variously arranged electrical conducting members. It being of course understood that this utility extends to difierent devices as well.

With reference to the disclosure of Fig. 4, it may be pointed out that the base units are preferably moulded to result in the finished form hegein shown. Inserts 18 are either set in the mould or later inserted and Screws 33 serve also to hold retained by a tight fit. End recesses or grooves 35 are provided so that when the screws 32 and those which hold the terminal clips to conductor bars 32 are threaded down, a resulting clearance is provided to receive the ends thereof Fig. 9 the screws 19c and 190 extend into these clearances). This is particularly useful in this construction as it allows for any slight variation in the length of the screws. Inasmuch as the various parts constituting the assembly of a hinged jaw or switch jaw terminal on each base unit are quite thin, having in some instances but one or two threads in the taps provided therein, it is obvious that-an undersized screw could not be used, no matter how slight the diiference would be. Consequently, provision permitting the use of a slightly oversized screw is desirable.

Referring how to Fig. 5, I have illustrated a grid which is perforated with variously shaped apertures. Three of these apertures may be positioned over blocks of the character shown in Fig.6, or blocks of different design, having longitudinal flanges along the edges of the terminal carrying face, as shown in Fig. 5. However, in Fig. 7, I have illustrated another type of base unit which may be desirable when it is necessary to mount 'a relatively complicated conducting member on a base unit. This base unit will be accommodated in the larger apertures of the grid 27.

It will be noted that the base unit shown in Fig. 7 is provided with an elongated recess 36 which is parallel to insert 18 and circular recesses 37. Insert 18', of course, receives the screw securing the conductor bar which carries the various parts constituting, in any particular instance, the clipcontact or terminal. Recesses 37 may be located directly beneath screws provided to hold a part or parts which have, more or less, a fixed position with respect to the base unit, while recess 36 is provided beneath a projecting screw of apart having a shifting position. In assembling switch bases, various factors must be taken into consideration. Voltage will control the distance between terminals, and in heavy construction, thickness of certain members will also alter the distance. Consequently, by allowing for such variations in constructing the base without requiring a multitude of difi'erent the base unit to be shifted slightly, so that it can be made to align with another base unit. It is here pointed out that the apertures in the (grid 26 may be cut accordingly, to accommo ate any change in the location of the base units, this being accomplished by providing blank grids and allowing the assembly men to cut the apertures as needed.

As before mentioned, in some switches I designs. The elongated recess 36 will permit unit, are preferably disposed opposite each other, and are adapted to have a metallic strap. '56 laid over their top faces, so that the nuts 57 of the screws 53 will bear against them instead of the flanges 51. Thus the tendency to fracture or crack the flanges 51,

as the result of threading the nuts 57 down fit over and contact peripherally on the screws 53 too far, is eliminated.

In building up a switch having these baseunits attached directly to the back wall of the enclosure, any desired spacing between the adjacent units may be easily obtained, and any required arrangement or v.disposition of them, relative to each other, can be had withoutdifiiculty.

In Fi s. 12 and 13 I have illustratedpractically t e same layout of base units. However, in this disclosure, the base units are constructed in a slightly different manner. Instead of the base unit anges being opposite each other andalong the longitudinal sides of the units, these flanges are oflset as indicated at 60 in Fig. 13. It is apparent that the usual advantages inoflsetting securing or supporting members are obtained herein. Twisting strains are more evenly distributed, and there is less opportunity for the units to disalign from each other, which renders imperfect contact between the blades of the switch and the terminal clip contacts.

Other variously designed base units may be furnished and arranged differently from those described herein if desired.

Without further elaboration, the forego- 'ing will so fully explain the gist of my invention, that others may, by applying current knowledge, readily adapt the same to use under varying conditions of service,

without eliminating certain features which may properl be said to constitute the essential items 0 novelty involved, which items are intended to be defined and secured to -me by the following claims.

Having thus described my 1nvention, what' I claim as new and desire to secure by Q ters Patent in the United States, is:

v, 1. Ina switch, a support, termiiral blocks,

means adapted to fit over and substantially peripherally surround said blocks, and

means to secure said last means to said sup-' port whereby said terminal blocks are firmly held in relation thereto.

2. In a switch, a support, terminal blocks having inclined sides, a member adapted to with said being firmly held by the engagement of the edges of said perforations with said inclined sides. 1

4. In 'a switch, a casing, insulating terminal blocks having non-parallel sides, and a perforate member secured to said casing, said blocks being firmly seated in said perforations of said members by reason of the enga ement of said block sides with said mem er.

5. In a switch, a casing, insulating ter minal blocks having shoulder portions formed thereupon, and a perforate member which is secured to said casing and is fitted down over said blocks, thereby holding said shoulder portions between said casing and itself.

6. In combination, electrical terminal mountings comprising a unit for each terminal, and means common to said units for arranlging them in predetermined position.

7. n combination, electrical terminal mountings comprisin units for each of the terminals, each unit aving a head portion, and a single member for lying over said head portions to hold said units in place.

8. In combination, a support, a plurality of electrical terminal mountin comprising insulation units secured to said support by a sin le member.

9. n combination,a support, 'a plurality of electrical terminal mountings, comprising insulation units secured in predetermined spaced relation on said support by a single member.

- 10. In combination, a support, a plurality of electrical terminal mountmgs comprising blocks of insulation and a metallic plate for spacing and securing said blocks to said support.

11. Electrical prising blocks of insulation and a plate for maintaining said blocks spaced by a contactual engagement only. i I

12. Electrical terminal mountings comprising blocks of insulation and a single member ,for holding said blocks spaced y lying .over a portion thereof.

13. Electrical terminal mountings comterminal mountings comprising blocks of insulaton for carryng the terminals, said blocks adapted to proj ect.partially through a single member for holding them in position. l

14. Electrical terminal mountings comrising a support-upon which a plurality of locks are arranged and held in position by a plate-like member.

15. Electrical terminal mountings com prising a-support upon which a plurality of mounts may be carried in various positlons blocks are arranged and held in position by wlth'respect to each other.

a single fastening member having a grip wltness whereof, I have hereunto subping ontact, SCIlbGd my name.

- 16. Electrical terminal mountings com- ALBERT BALL- prising a support upon which blocks of m-' sulation are arranged and held in posit on by a single fastening member having a grlpping contact, said fastening member bemg secured to said support.

\ 1'1. An electrical terminal base comprising a support, a plurality of blocks of insulation loosely arranged on said support, a grid adapted to be laid over said blocks without obstructing terminal facesprovlded therein for carrying terminal members, and securing means between said support and said grid for holding said blocks in position.

18. An electrical terminal base comprising a support having arranged thereon a plurality of blocks provided with terminal faces, and a member having openings substantially of the same configuration as said terminal faces and holding said blocks upon said support.

19. An electrical terminal base comprising a support having arranged thereon a plurality of insulation blocks provided with terminal faces, a member having'openings through which said blocks roject, said 0 enings being substantially 0 the same con guration as said terminal faces, and securing means projecting from said member into said support.

20. In a device of the class described, a support, a plate, a plurality of individual mounts between said support and saidplate, said mounts being held in spaced relation by said plate,

40 21. In a device of the class described, a support, a substantially parallel plate-like member, a plurality of individual mounts having portions thereof substantially parallel to said support and said plate, said par allel portions lying between said support 110 and said plate whereby displacement of said mounts is prevented.

22. In a device of the class described, a support, a substantially parallel plate-like member, a plurality of individual mounts 115 each having a portion thereof substantially parallel to said support and said plate and a portion transverse to the parallel portion,

said parallel portion being disposed between 120 said support and said plate, said transverse portion extending through and lying in projected relation to said plate.

23. In a device of the class described, a

support, a plate, a plurality of individual 12 mounts carried between said support and said plate, said plate being provided with a plurality of openings through which said mounts project, certain of said openings ly- ()5 ing at an angle to the others so that said I". 

